Learn Hardcore Russian: Его сестра более стеснительная, зато она внимательно слушает собеседника. - His sister is more shy, but she listens attentively to the person she is talking to.

Analytic (with более “more”):
- более стеснительный / более стеснительная – more shy
Synthetic (single-word comparative):
- стеснительнее – shyer

In this sentence, you could also say:

Его сестра стеснительнее, зато она внимательно слушает собеседника.

Both versions are grammatically correct.

Nuance:

стеснительнее sounds a bit more colloquial and neutral.
более стеснительная can sound a little more formal or careful, and keeps the full adjective form (which can feel slightly more descriptive).

Why is there a comma before зато?

Зато is a coordinating conjunction here, similar to “but / however / on the other hand / but at least”.

In Russian, a comma is usually placed before coordinating conjunctions that connect two independent clauses (each with its own subject and verb).

Clause 1: Его сестра более стеснительная (subject + predicate)
Clause 2: (зато) она внимательно слушает собеседника (subject + predicate)

Since each part could stand as a separate sentence, a comma is required before зато.

What is the difference between зато and но here? Could we use но instead?

You can say:

Его сестра более стеснительная, но она внимательно слушает собеседника.

It is grammatically correct, but the nuance changes slightly:

но = “but” in a neutral, contrastive way.
зато = “but / however / on the other hand / but at least”, with a compensating idea: something negative is balanced by something positive.

So the meaning with зато is more like:

“His sister is more shy, but (on the plus side) she listens carefully to the person she’s talking to.”

With но, it’s just a simple contrast, without the “compensation” flavor.

Why is it его сестра and not something like его сестру or его сестры? What case is this?

Его сестра is in the nominative case:

сестра – nominative singular (subject of the sentence)
его – possessive pronoun “his”, and it is indeclinable: it does not change form for case, gender, or number.

So:

его сестра – his sister (subject)
Его сестра более стеснительная. – His sister is more shy.

Different cases would be used if the sister were an object:

Я вижу его сестру. – I see his sister. (accusative)
Я боюсь его сестры. – I am afraid of his sister. (genitive)

Here, since she is the subject, сестра must be nominative.

Why is стеснительная feminine? What is it agreeing with?

In Russian, adjectives agree with the noun in:

gender (masculine, feminine, neuter)
number (singular, plural)
case

Сестра is:

feminine
singular
nominative

So the adjective стеснительная also appears as:

feminine
singular
nominative

Hence его сестра более стеснительная:

сестра (fem. sing. nom.)
стеснительная (fem. sing. nom.)

Why is there no word for “is” in Его сестра более стеснительная?

Russian usually omits the verb “to be” in the present tense when stating what something is:

Его сестра более стеснительная. – literally “His sister more shy.”
English: “His sister is more shy.”

In the past or future, Russian uses a form of быть (“to be”):

Его сестра была более стеснительной. – His sister was more shy.
Его сестра будет более стеснительной. – His sister will be more shy.

But in the present, the verb “to be” is typically dropped in such constructions.

What does зато она внимательно слушает собеседника express about time? Is слушает present, habitual, or something else?

Слушает is present tense, imperfective aspect.

In Russian, present imperfective can express:

an action happening right now
or a repeated / habitual action

Here it clearly has a habitual meaning:

“She (generally) listens attentively to the person she is talking to.”

So the sentence describes her characteristic behavior, much like English present simple (she listens).

Why is it собеседника and not собеседник? What case is this, and what does собеседник mean?

Собеседник means “interlocutor, conversation partner, the person you’re talking to.”

Its forms (singular, masculine animate):

Nominative: собеседник – (subject)
Accusative: собеседника – (object, animate)

In Russian, animate masculine nouns have accusative singular = genitive singular form. So собеседника here looks like genitive but functions as accusative (direct object):

Она слушает собеседника. – She listens to the interlocutor.

Thus собеседника is the accusative case of an animate noun.

Could we drop она in the second part and just say: … зато внимательно слушает собеседника?

Yes, you could say:

Его сестра более стеснительная, зато внимательно слушает собеседника.

In Russian, the subject pronoun is often omitted when it is clear from context who is acting.

Difference:

With она: a bit more explicit, slightly more formal or careful:
- … зато она внимательно слушает…
Without она: more compact, still natural and clear here.

Both are correct; it’s a matter of style and emphasis, not grammar.

What is the difference between слушать and слышать? Why is слушает used here?

слушать = to listen (intentionally)
слышать = to hear (perceive sound, not necessarily intentional)

Since the sentence talks about a positive trait – that she pays attention to the other person – we need the verb indicating active, focused listening:

она внимательно слушает собеседника – she listens carefully to the interlocutor.

Using слышать here would be strange; it would mean only that she physically hears them, not that she pays attention.

What is внимательно exactly? Is it an adjective or an adverb, and why is it placed before слушает?

Внимательно is an adverb meaning “attentively, carefully.”

Adjective: внимательный – attentive (e.g. внимательный человек – an attentive person)
Adverb: внимательно – attentively (e.g. внимательно слушать – to listen attentively)

Adverbs in Russian usually stand before the verb or right after it. Here:

она внимательно слушает собеседника
- внимательно modifies слушает and tells us how she listens.

Can we change the word order, for example: Она внимательно слушает собеседника, зато его сестра более стеснительная?

Yes, this alternative order is grammatically possible:

Она внимательно слушает собеседника, зато его сестра более стеснительная.

However, the meaning becomes a bit odd, because the pronouns and nouns no longer line up naturally:

Original sentence: her shyness is the “minus”, her attentive listening is the “plus”.
Reversed sentence: “She listens attentively, but his sister is more shy” – sounds like we’re contrasting one person (“она”) with another person (“его сестра”), which is a different relationship.

In the original, both clauses clearly talk about the same person (his sister). The order supports that interpretation most naturally.

Could we use застенчивая instead of стеснительная? Is there a difference?

You could say:

Его сестра более застенчивая, зато она внимательно слушает собеседника.

Both стеснительная and застенчивая mean “shy, timid.”

Nuance (often subtle and context-dependent):

стеснительная – shy, easily embarrassed, self-conscious
застенчивая – shy, more about social awkwardness or reluctance to step forward

In many contexts, they are near-synonyms. In this sentence, either works, but стеснительная is very common and neutral.